Process of producing hydrochloric acid.



following is a specification.

UNKTEE dTATES PAEE canton.

JOHN H. NIELD, F HACKENSACK, NEW JERSEY, ASSIGNOR TO GENERAL CHEMICAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF PRODUCING HYDROCHLORIC ACID.

No Drawing.

Specification of Letters Patent.

Application filed August 21, 1909. Serial No. 5145629.

Patented ma a, rate.

To all whom it mag concern:

Be it known that I, JOHN Hnunnn'rNmLn, a citizen ofvthe United States, and resident of Hackensack, county of Bergen, and State of New Jersey, have invented certain new and useful Improvements in Processes of Producing Hydrochloric Acid, of which the The object of thisinvention is to provide a process for the production of hydrochloricacid by the action of sulfuric acid upon sodium chlorid, hereinafter termed common salt, in such a. manner that a fluid or semi-fluid intermediate condition or state of the materials does not occur and which thereforecanbe practised commercially in a continuous manner.

In the heretofore successful commercial process for the manufacture of hydrochloric acid by the action of sulfuric acid upon common salt, the operations are conducted in two stages and are therefore intermittent or discontinuous and this intermittent nature of these processes has manufacturing disadvantages which it is the purpose of this invention to minimize or remove.

Now I. have discovered that if common salt is suitably mixed with a suitable amount 'of a suitable inert material such as salt cake, it can be acted upon by the requisite amount of sulfuric acid to convert substantially the entire amount of common salt into hydrochloric acid without a liquid or semiliquid state intervening and thatfrom start to finish the mixture remains sufliciently firm and hard so that it may be propelled or moved over a suitably hcatcdsurface by means of devices such as rakes, moved by machinery or by hand (preferably the former); by moving the material from the cooler to the hotter and finally to the hottest portions of the heated surface it is possible continuously to treat common salt with sulfuric acid so as to evolve continuously hydrochloric acid and ,to the full extent usually obtained commercially.

The process I have invented and based upon the discovery has, as compared with the commercial process heretofore used for this purpose, the following advantages:

drochloric acid product. 4. Smaller losses of unacted-on common salt or sulfuric acid in the solid residue. 5. Less time is required for the commercial] complete decomposition of a charge 0 materials. 6. Continuous evolution of hydrochloric acid gas in a high degree of concentration. 7. A. substantially constant regular amount of work put upon the absorption apparatus of the plant, combined with higher-efi'iciency and more easily controlled operation of this absorption plant. 8. Less manual labor, since the process can be carried out in a suitable mechanically operated furnace. 9. Less hardship upon the laborers and the surrounding vegetation and habitations, due to escape of hydrochloric acid decomposing apparatus.

I now proceed to illustrate my invention by the following example, but in so doin I am to be understood as not being" limited to the precise conditions therein set forth.

I have found that a satisfactory mixture can be obtained as follows: Common salt 50 parts, salt cake 50 arts, are separately ground, then thorough y mixed and finally passed through a 20 mesh screen and the gas from the product mixed with its equivalent weight of sulfuric acid containing 93%% H SO The mixture when produced, is placed upon a heated surface, for example the bottom of a mutlle heated at its hottest part to about 1000 F. and gradually moved over the muffle bed by means of rakes propelled by hand or machinery from the cooler portion to the hottest portions of the mufile; at the end of about one hour the decomposition will be found to be commercially complete.

While my process may be carried out in various types of apparatus, I preferably employ an apparatus such as described and claimed in my U. S. Patent No. 1,033,825, dated July 30, 1912.

The above described apparatus constitutes the subject matter of a separate ap lieation for patent filed August 6,1909, Ser. A 0. 511,510.

I claim:

1. The process of making hydrochloric acid which comprises treating with sulfuric acid, a mixture of common salt and a pub verulent, substantially inert material; the latter being in amount suficient to prevent substantial amount of liquefaction of the reacting materials at any stage of the process. 7

2. The process of making hydrochloric parts of common salt and salt cake, until the conversion of the common salt and sulfurlc'acid into normal sodium sulfate and hydrochloric acid is substantially complete and while substantially avoiding liquefaction of the mass at any stage of the process.

4. The improvement in the art of manufactoring hydrochloric acid from common salt and sulfuricacid which consists in heating to the requisite temperature a mixture of-such substances and'a neutral substance, thus permitting substantially all of the sulfuric acid and of the common salt to react with each other, to. form salt cake and hydrochloric acid, and thereby avoiding the formation of a pasty mass and the conseq uent stoppage of the operation, substantlally as and for the purpose described.

5. The improvement in the art of manufacturi ng hydrochloric acid from common salt and sulfuric acid which consists in heatin ture of permitting substantially all-of the sulfuric acid and of the common salt to react with each other, to form salt cake and hydrochloric acid, and thereby avoiding the formation of a pasty mass and the consequent stoppage of the operation, substantially as and for the purpose described.

6. The process of making hydrochloric acid, which comprisesv progressivelyheat ing, to a temperature at which the reaction between common salt, and sulfuric acid is substantially complete, a mixture of sulfuric acid and common salt, while containing a sufficient amount of an inert solid material, to prevent the formation of a liquid or pasty mass, while progressively moving said mass into locations havingprogressively increas;

ing" ten'lperatures. r

7 The process of making hydrochloric acid, which comprises progressively heat ing to a temperature at which the reaction between. common salt and sulfuric acid is substantially complete, a mixtureof sulfuric acid and common salt, While containing a suflicient amount of salt cake to prevent the formation of a liquid or pasty mass, while progressively moving said mass into locations having progressively increasing tem peratures.

8. The process of making hydrochloric acid, which comprises progressively heating to an ultimate temperature of about l000 1 a mixture of sulfuric acid and common salt, while containing a sufficient amount of an inert solid material to prevent the formation of a liquid or pasty mass, while progressively moving said mass into locations having progressively increasing temperatures. to the requlsite temperature a mix r such substances and salt cake, thus In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

J. H. NIELD. Vvitnesses:

BERNHARD C. Hnssn, Furrz. v. BRIESEN. 

